Answer:
The idea proposed by Lamarck that was rejected by his fellow scientists is "Acquired traits can be passed to offspring."
Step-by-step explanation:
Lamarck believed that organisms could pass on traits they acquired during their lifetime to their offspring, a theory known as the inheritance of acquired characteristics. However, this idea has been widely discredited by the scientific community since it does not align with the principles of genetics and heredity. The traits that are passed down to offspring are determined by genetic information passed on through the reproductive cells, not by the environment or lifestyle of the parent.